Could this signal the return of 100% mortgages? For the first time in more than 18 months, first-time buyers will be able to get on to the property ladder without having to put down a deposit, following the unveiling this week of a shared-ownership scheme.

Mansfield building society has teamed up with South Yorkshire Housing Association to offer buyers the chance to borrow up to 100% of their share of the purchase price. Initially, you own up to 60% of the property. The housing association retains 40% and the buyer pays rent on this. Purchasers will be able to increase the share they own over time, although a separate report this week found that many tenants find it difficult to "staircase" up the ownership ladder.

The scheme is aimed at social housing residents and key workers. Based in Sheffield, South Yorkshire Housing Association has almost 5,300 properties spread across Yorkshire, Derbyshire, Nottinghamshire and Lincolnshire.

Mansfield CEO Nigel Quinton says of the deal: "A major feature is that it allows purchasers to borrow the full amount of their share of the purchase price." The housing association says there is no shortage of people who want to get their foot on the housing ladder – the problem is raising the deposit. "We hope other organisations will take up this model, and that it can provide a shot in the arm to the local affordable housing market," it adds.

The mortgage is a five-year fixed-rate at 5.99% with no arrangement fee. David Black, banking specialist at financial analyst Defaqto, says: "This must be the first time for more than 18 months that someone can get on the property ladder without any deposit."

He estimates roughly 30% of current mortgage products are available for shared ownership – though he points out that not everyone will be comfortable with this type of arrangement. The average maximum loan-to-value (LTV) for shared ownership is 75%, and Black says the highest LTV he could find for new borrowers is 90%, from Abbey.

The launch coincided with research from Moneyfacts revealing a 75% fall in the number of loans available over the past year to those with just a 10% deposit.